This application claims priority under 35 U.S.C. .sctn. 119 of European Patent Application No. 97203280.9, filed in the European Patent Office on Oct. 23, 1997.
The invention relates to a catheter device for the treatment of a vessel carrying body fluid, comprising an inner first occlusion catheter, having a first tubular shaft with a proximal end and a distal end, a distal occlusion balloon disposed at the distal end of the first tubular shaft and an inflation lumen extending through the first tubular shaft between a proximal entry at the proximal end and a distal exit inside the distal occlusion balloon, and an outer treatment catheter, having a second tubular shaft with a central lumen extending therethrough for coaxial reception of the first occlusion catheter, and being longitudinally displaceable with respect to the first occlusion catheter.
A catheter device of the kind mentioned in the introduction is known for example from U.S. Pat. No. 5,423,742 which is used for percutaneous transluminal angioplasty of arteriosclerotic deposits or atheroma in the carotid artery. For this treatment an outermost guide catheter is pushed through an opening in the inguinal region of the patient into the vessel, until its front opening is situated directly in front of the stenosis. An innermost occlusion catheter is then inserted into the guide catheter and placed in a way that the occlusion balloon can be stabilized in the inflated state distal of the stenosis. A central dilation catheter is then pushed over the occlusion catheter, and the dilatation balloon is positioned in the middle of the stenosis which is now dilated in a known manner. Vessel parts which might be detached during angioplasty are prevented by the occlusion balloon from getting into the narrow and tortuous cerebral vessel system reducing thereby the risk of embolism.
After treatment of the stenosis the dilatation balloon is emptied and the dilation catheter is retracted. With the occlusion catheter simultaneously inflated, vessel fluid and any detached particles present are removed by suction through the guide catheter by means of a syringe. As a result of pressure exerted by means of the syringe, vessel fluid with small particles can be washed out reaching areas of the vessel where there is no danger of embolism. Finally, the occlusion balloon is also returned to the emptied state and the catheter device is removed from the vessel.
For inflating and deflating the occlusion balloon a syringe is connected to the proximal end of the occlusion catheter. The latter must have a length greater than the length of the guide catheter plus the length of the dilation catheter, for example between 250 and 300 cm, to allow the dilation catheter being withdrawn over the occlusion catheter completely out of the guide catheter, while the occlusion balloon remains in its inflated condition. The syringe connector which might be a stop cock combines the occlusion catheter and the dilation catheter to a unit which shows disadvantages if further treatment, such as stenting or post-dilating of the widened stenosis, is necessary. The catheter unit does not allow the exchange of the dilation catheter by another catheter during the protective occlusion balloon is kept in its inflated condition, since the connector forms an obstacle which cannot be passed through the central lumen of the dilation catheter. Thus, in such a case the whole catheter unit must be replaced. On one hand this might be a rather time consuming procedure putting a lot of stress to the patient. On the other hand it raises the risk of embolism since the protective downstream occlusion of the vessel has to be interrupted.
All documents cited herein, including the foregoing, are incorporated herein by reference in their entireties for all purposes.